1. Field of the Invention
The present invention relates to a magnetic recording/reproducing apparatus and, more particularly, to a small-size, light-weight magnetic recording/reproducing apparatus in which a magnetic tape cassette is used, e.g., a VCR (Video Cassette Recorder), a camera recorder, or a digital audio tape apparatus (DAT) for household use and business use.
2. Description of the Related Art
Concerning cassette-type magnetic recording/reproducing apparatus represented by camera recorders, weight reduction has been strongly demanded. In order to realize this weight reduction, there have conventionally been taken measures such as decreasing the plate thickness of a chassis, using a material such as aluminum having a smaller specific weight than iron and iron alloy, and shaping the chassis to have a high percentage of cut-out portions or holes. Materials and shapes of conventional chassis are disclosed in, for example, Japanese Patent Unexamined Publication No. 61-271648.
With the conventional chassis structure, the rigidity of the chassis is deteriorated if the plate thickness of the chassis made of aluminum material is decreased or if cut-out portions or holes are formed in the chassis so as to achieve the weight reduction. Therefore, during operation of the apparatus, the chassis is deformed by reaction force of springs for positioning a tape cassette, force exerted on contact points between the tape cassette and the chassis, and so forth. Due to such deformation of the chassis, the accuracy in the traveling position of the tape is deteriorated, which eventually results in problems such as degradation of the recording/reproducing performance with respect to the tape.
As an exterior type casing on which the chassis is fastened, an article molded of plastic is often used. Since its rigidity is low, the exterior type casing is easily deformed when a strong force is applied to it during use of the apparatus. The force is also transmitted to the chassis through fastening portions, and consequently there is a possibility that the accuracy of the chassis will be deteriorated. Moreover, the shape accuracy of the exterior type casing which is an article molded of plastic is inferior to that of the chassis made of aluminum material or the like. Therefore, variation in the shapes of those portions of the exterior type casing to be fastened on the chassis occasionally causes deformation of the chassis at the time of fastening, thus deteriorating plane accuracy of the chassis.